Spark-plug.



will enable others skilled in the art to which oHARLEs A. -MEZQGE 0F' NEW YORK, N. Y.

sientan-Praia.`v

To all 'whom it may concern: .l Be it know-n that l, Cuantas A. Mnzosn, ofthe boi--v ough of Brooklyn, citylol New York, county of Kings, and State of New York, have invented certain new and useful Improvements in Spark-Plugs, of which the following is a full, clear, and exact specification, suclias i it appertains to make and use the same.

` My invention relates to an 'improvement in spark plugs particularly of the type employed in what is `termed the jump spark or high tension system of ignition in gas and oil'engines.

The principal object of my invention is to improve the devices for effecting a hermetic connection between the porcelain insulation and the body or shell of the plus VIn carrying out my invention I construct the bushing of the plug in the usual manner and I provide a non- K i t. rotary soit metal annulus which cncircles the porcelain ror other insulation and bears between the inner end of thel bushing and the-usual enlargement on the insulaF tion s o that as the bushing is screwed, home` the soft metal annulus is expanded or contracted, or otherwise vso causedto cliange its fonnf'ldiametrically against the enlargement on the insulation and alight joint is thereby effected, the bushing turning freely on theannulus,

and the annulus having no'movelnent but an expanding'or contracting movementlongitudinal on the porcelain. With this arrangement should there be an imf perfection in the 'porcelain such for instance as an uneven projection on the surface thereof, the annulus expands orcontracts'over the proj ection and forms a tight joint at this as well as at the other points,

Reference is now had to the accompanying drawings, which illustrate, as an example, two practical embodiments of my invention, in which drawings:

Figure l isa longitudinal section of the plug in which the annulus is adapted to be expanded over the enlarge insulation usually ofv porcelain surrounding the po:-:i-,

menton the porcelain; Fig. 2 a longitudinal section showing a form ofthe invention in which tl'. e annulus is engaged by the bushing and adapted to be crowded in `aroundthe porcelain; Fig. 3 isasection showing a slight modification in the form of the annulus, and, Fig. 4 is a i section of the same when forced home.

In Fig. l u indicatcs the shell or body of the spark plug as will be understood from the prior art, the

-tive electrode c. 'The porcelain sleevrd l; is provided `within the shell 'L with an annular .nlargomont b tapering at its upper and lower sides and screwing into the outer end of the shell a and surrounding the i t porcelain sleeve b is a bushing r1. A suitable packing e usually of asbestos bearsy between the underside oi l the enlargement b/ and an interior shoulder e on the yshell a. f indicates the annulus. This is formed of Specification of Letters Patent. Application tiled December 26,1908. Serial No. 349.605.

ententes Aug. 2o, 1907.

soft metal such as copper or brass and lit engages the i tapering upper side of the enlargement .b the inner end of the bushing d turning lfreely on the annulus.

Upon assembling the parts of the plug and screwing in the bushing rl, the bushing rotates smoothly on the annulus and crowds the same down over the enlargement b" the annulus spreading or upsetting over the same and effecting a hermetic connection. Should the porcelain, as is frequently the raso, have a slight unevenness or projection at the point V, the soft metal (l5v projection b of the porcelain b and the bushing d has a sharp inner edge (Il which embraces and engages the annulus. Upon tightening up the bushing, its edge d2 75 turns freely on the annulus which has no movement other than a slight crowding movement longitudinal of the plug` This operation' muses the annulus to be contracted against the insulation and a hermetic joint 4 I S0 effected.

In Figs. 3 and 4, thesoft metal annulus f2 has a ,tapered lower edge substantially similar to that slioft'rnu l in Fig. 1, at which edge the beveled surface f is im" portant. The upper edge of the annulus is beveled as indicated at f3, the beveled surfaces js and f4 ex- 85 tending from the outer to the, inner surface of the annulus in the same direction. The arrangement is such that the beveled surface f4 at the lower edge ei'lgages the enlargement on the porcelain while ,the

beveled surface f 3 at the upper edge of the annulus is 90 engaged and (as shown in Fig. 4) inclosed by `the bushing. Before compression, this annulus j'2 stands slightly away from the porcelain (see Fig. 3). When,` however, pressure is applied, not only does the beveled lower ed e f 'read out over the taper of the por- 95 colain. but the beveled edge,"3 is contracted orar/:rowded in against the porcelain and avdouble pacldngref sults as is indicated in Fig. 4.

In all forms oi' the invention here illustrated; it

will be observed that the essential principle running through the invention is the .relative action of the bushing and annulus in which the turning movement is substantially confined to the bushing, the annulus boing left to expand or contract or otherwise 'change its forni diametrically by movement longitudinalV of the plug, insuring enveloprnent, so to speak, of any projections or other imperfections in the porcelain and resulting thereby in a perfect connection.

Having thus specifically described the preferred embodimentof my invention, what I claim as new sind (il Slim-s;

i. iu n Spark ping, n slioil or body, :in insulation mvmbnr iiierein with an annular oni-argument, a' bushing 'rrfwving into tho shell and surrounding the insulation lne-mlmr :ind iin aumilus o relatively soft metal surrounding i'ho insuiaiion uwuiber at said Quim-ged portion, the :mnulus having its edges bovelod in tiio Samir direction. one {oflsuci'i-fdges sngnging'iiie enlargement of the insu-- intimi and tin: ofiier edge being engaged by the bushing. wi'ielolf' when the bushing is screwed boule, the imuuius i: housed to expand :igninst the vulnrged portion of the insulation imd 'to (ontrack against the muin 'portion of the insuiation.

2. In'flsrinrk plug u shell or body, au insulation member e. iriug centrally through ille same and formed to soeuro by Lettors P11-teni, of the United /wiih :in annular enlarizme'nt, a bushing screwing into the ieii and surrounding tifo insulation member and non-roinive nniuius of relatively soft metal surrounding im insulation .member adjacent to Suid enlarged portion lzum engaged amd partly ineiosed by the bushing, aid an- 'poso specified. i

nulus being' adapted under the prs`s1uof the bushing to' ba contracted against the inuiation lnemiiegfor the pur- Y 1Min a spark plug, a sileii or body, ran' insulation member rgteuding centrally through thc Sommand having :in 'annular Pniurfzonmni. ul bushing screwing info the shell and surrounding-f i'iua in \1l:ition.membe'r, and n nonroiniire unnulus of roiiitiv 1 softv metal Surrounding,r the insuiiitimi mvmbl-r :idjuconij vilo s'z'iid onlzirigod portion with which aminlus tim iunvr vnd of the bushing has siiding'- engugnm t, \\'l\ornb v :is rbc bushing is screwed home. the annui;\isfi icro\wie by u non-rotativo .movement against the; enlargement of iheinsuiniion member in a direction longitudinal 'of the plug and said annuluu is aused to c imngc its` form diametricnlly-f0r tho purpose specified.

In testimony whereof7 I have signed my name to this specification in the presence of two subscribing witnesses.

ISAAC B. OWENS, E. i. MCLAUGHMN. 

